What are two possible fates of stars larger than 8 sol

One type of breathalyzer employs a fuel cell to measure the quantity of alcohol in the breath. When a suspect blows into the bre

Alekssandra [3086]

Response:The ethanol percentage is 0.1093%

Explanation:

As given:

t = time = 10 s

I = current = 320 mA

F = Faraday's constant = 96485.3365 C mol⁻¹

n = number of electrons transferred = 4

Molecular weight of ethanol is 46 g/mol

Question: What is the percent (by volume) of ethanol in the driver's breath, %E =?

First, calculate the ethanol mass:

$W=\frac{\frac{46}{4} *0.32*10}{96485.3365} =3.814x10^{-4} g$

The moles of ethanol:

$n_{ethanol} =3.814x10^{-4} g*\frac{1mol}{46} =8.291x10^{-6} moles$

Applying the ideal gas law formula:

$V=\frac{nRT}{P}$

Here:

T = 26°C = 299 K

P = 1 atm

Substituting in the values:

$V=\frac{8.291x10^{-6}*0.082*299 }{1} =2.033x10^{-4} L=0.2033mL$

The percentage of ethanol:

$E=\frac{0.2033}{186} *100=0.1093$ %

3 0

2 months ago

20 point, pls help. A 5.50 mole sample of a gas has a volume of 2.50 L. What would the volume be if the amount increased to 11.0

Anarel [2989]

Sagot:

Dapat mong suriin ito, isang mahusay na pagkakataon ito para sa iyo upang ipaalam sa mga kasapi ng iyong pamilya at magiging masaya akong tumulong sa iyo sa prosesong ito kung ikaw ay mayroong mga katanungan o alalahanin tungkol sa dad lowkey o kung kailangan mo ng tulong sa proyekto o kahit ano pa, sabihin mo lang sa akin kung ano ang kailangan mong ipagawa

5 0

1 month ago

A 250. ml sample of 0.0328m hcl is partially neutralized by the addition of 100. ml of 0.0245m naoh. find the concentration of h

lions [2927]

Answer: 0.0164 molar concentration of hydrochloric acid in the resulting solution.

Explanation:

1) Molarity of 0.250 L HCl solution: 0.0328 M

$Molarity=\frac{\text{Number of moles}}{\text{Volume of solution in liters}}=0.0328=\frac{\text{Number of moles}}{0.250 L}$

The amount of HCl in the 0.250 L solution = 0.0082 moles

2) Molarity of 0.100 L NaOH solution: 0.0245 M

$Molarity=\frac{\text{Number of moles}}{\text{Volume of solution in liters}}=0.0245=\frac{\text{Number of moles}}{0.100 L}$

The amount of NaOH in the 0.100 L solution = 0.00245 moles

3) Determining the concentration of hydrochloric acid in the final solution.

0.00245 moles of NaOH will neutralize 0.00245 moles of HCl from the original 0.0082 moles of HCl.

The total volume of the mixture becomes 0.100 L + 0.250 L = 0.350 L

Remaining moles of unreacted HCl = 0.0082 moles - 0.00245 moles = 0.00575 moles

$Molarity=\frac{\text{number of moles}}{\text{volume of solution in L}}$

Concentration of the remaining HCl: $\frac{0.00575 moles}{0.350L}=0.0164 M$

0.0164 molar concentration of hydrochloric acid in the resulting solution.

3 0

2 months ago

The standard heat of combustion of ethanol, C2H5OH, is 1372 kJ/mol ethanol. How much heat (in kJ) would be liberated by complete

alisha [2963]

Answer:

The accurate answer is 596.5 kJ.

Explanation:

The question specifies that the mass of ethanol, C2H5OH, is 20 grams.

The molar mass of ethanol is 46 g/mol.

To find the moles of ethanol, we use the formula:

n = mass / molar mass

= 20/46 = 0.435 moles

According to the question, the standard heat of combustion for ethanol is 1372 kJ/mol. Hence, one mole releases 1372 kilojoules during combustion.

The energy produced from burning 20 grams of ethanol completely is 0.435 * 1372 = 596.5 kJ.

4 0

2 months ago